This research project is designed to study factors governing lipoprotein metabolism both in the normal state and in individuals with genetic forms of hyperlipidemia who have or are likely to develop atherosclerosis. The project will involve the use of several animal species in addition to man and studies are broadly divided into physiologic and pathophysiologic areas. In physiologic studies, parameters of lipoprotein metabolism in human subjects will be established. Emphasis will be placed on defining synthesis and degradation rates and on outlining lipoprotein interconversions within the plasma space. The baboon, a sub-human primate, will be utilized to study lipid and protein metabolism simultaneously. In pathophysiologic studies, humans with autosomal dominant forms of inherited hyperlipoproteinemia and atherosclerosis will be investigated to define defects in lipo-protein metabolism. Various treatment modalities will also be evaluated with regard to their effects on lipoprotein metabolism. The influence of the intestine on lipoprotein metabolism will be investigated in the baboon with ileal diversion or jejunectomy.